How soon can you weed and feed new grass?

You cannot apply weed and feed to new grass. Weed and feed will kill any new grass growth. Weed and feed is not organic and will seep into your neighbors lawns as well, so it would be a good idea to consider you neighbors before applying weed and seed. I don't recommend using it at all.

it depends on weather you can weed new grass after a month and you can feed a new grass after 6 months it depends on the quality of the grass used.. weeding of new grass wont be required soon as the grass is new usually new grass is required after winter